Conventionally, a mobile phone comprises control, audio, power, input, output, and wireless receiving circuits. The mobile phone is designed to enable both distant persons having a mobile phone to communicate each other. The circuits are enclosed in a housing as a whole so as to facilitate carrying the mobile phone and using same. The housing is typically made of plastic material and is formed by typical molding or injection molding. Thus, it is possible of mass producing mobile phone housing of high quality, low cost, and lightweight in a short time. Further, some types of mobile phone housing are made of alloy and are formed by manually polishing or lathe machining. Such mobile phone housings are robust, durable, and high quality.
However, whether made of plastics or alloy, mobile phone housing is subject to damage (e.g., breakage, peeling, or corner breakup) when the mobile phone collides with a hard object (e.g., falling to the ground). As a result, mobile phone appearance and structure may be adversely affected. A plastic enclosure adapted to fit around a typical mobile phone is thus invented by some manufacturers of the art. The enclosure serves as a protection for lessening the effect or absorbing the force of shocks and jarring when the mobile phone collides with a hard object. However, the plastic enclosure has disadvantages including being expensive, increasing weight and size of the mobile phone, and being inconvenient in carrying. Moreover, the plastic enclosure is adapted to closely wrap the mobile phone around. Thus, only one type of plastic enclosure conforms to a specific type of mobile phone. This in turn greatly increases the manufacturing cost. Moreover, it is very difficult of replacing a worn plastic enclosure by a mobile phone user. Thus, it is desirable to provide a handheld electronic device having a pad-based shockproof mechanism to prevent the handheld electronic device from being damaged after hitting a hard object (e.g., falling to the ground) in order to overcome the inadequacies of the prior art.